Method of calcining rock



2 SheetsSheet 1.

(No Model.)

G. E. GARLETON.

METHOD OF GALUINING ROCK.

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(No Model.)

G. E. GARLETON.

METHOD OF GALGINING BOOK.

No. 399,496; Patented Mar.'12, '1889.

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GRANVILLE E. CARLETON, OF ROCKPORT, MAlNE.

METHOD OF CALCINING ROCE.

SPECIFICATION forming part of Letters Patent No. 399,496, dated March 12, 1889.

Application filed July '7, 1888. Serial No. 279,310. (No model.)

To aZZ whom it may concern.-

Be it known that I, GRANVILLE IIC. (Lu- Ln TON, of Rockport, in the county of Knox and State of Maine, have invented a new and useful Improvement in the Method of Calcining Rock; and I do hereby declare that the follOW'll'lg is a full, clear, and exactdescription of the same.

My invention relates to calcination of limestone for the n'iz'iinufacture of lime or cement in the kilns. The object of it is to produce a better draft, perfect combustion of the fuel, and a more even and uniform distribution of the heat in the barrel of the kiln, whereby the stone is thoroughly calcined without injury to the kiln and the fuel is thoroughly and economically utilized.

The invention is designed, chiefly, for use in connection with coal. as a fuel, and in this connection it operates with the best effect; but it is not necessarily con fined to coal alone, but may be used in connection with wood as a fuel, or with wood and coal mixed.

The use of coal as a fuel in kilns for calcining lime has heretofore been attended with difficulty in respect to the draft, and also in respect to its action upon a stone. In my ex-- perience with this kind of fuel I have applied a blast underneath the grate, which, while it increased the draft, caused the heat to act imperfectly and unevenly upon the stone in the barrel of the kiln. I have found by further experiment that this difficulty attending the use of the air-blast may be overcome by the use of the jet of water or steam applied in front of or over the bed of coal in the [irechamber; and my invention as set forth, in this specification mainly consists in the method of calcining stone for the manufacture of lime or cement by means of an air-blast applied underneath the :fuel and the spray or jet of water orsteam applied to the fuel within the tire-box.

I have shown in the acconipanying drawings the apparatus by means of which my in vention is most conveniently practiced; but I do not confine myself to the use of this apparatus, and it forms no part of my present invention, being the subject of the application filed in the United States Patent Oificc of even date herewith, Serial No. 270,309.

In the drawings, Figure 1 shows a vertical section taken through the center of the arches and through the barrel of the kiln. Fi 2 shows a horizoi'ltal section of the kiln on line a; of Fig. 1. Fig. shows a view of the arch- Fig. l, a view of the opening of the arch froni the inside of the barrel. Fig. 5 shows a perspective view of the kiln, and Fig. 6 a detail section of the nozzle for supplying the water I or steam jet.

In the drawings, A represents the barrel of f-l1Qkll]l,{1ll(l thearches. The general construction and arrangement; of these arches in their relation to the barrel in the kiln are the same as those in ordinary use; but for the better operation of my invention I have chan ed somewhat the proportions of the parts 5nd although I do not limit myself to the xact proportions I have hereinafter given them in order that: those skilled in the art niav beable to better practice my invention I have repsented the barrel of the kiln as havin a rear and cross section of five by seven feet. The height of this kiln is the same as those in ordinary use (about thirty-two feet) havin the same crosssection. The kiln represented is what is ordinarily called the four-arch kiln there being four arches-two on each sideopening into the barrel of the kiln. Each of these arches is about thirty inches in width and twenty inches in height, it being desi ned for coal, and therefore requiring dnly about twothirds of the height required in an arch used for burning wood. The pillar used for supporting the arch at the opening into th barrel is represented at l). The openin s (1 on each side of this pillar are ten inches i vide and eighteen inches high, a fire-brid e about two inches in height, as shown at bein placed across the openings. The grate showil in the plan view of the arch ex tends from side to side and is about twentv bv tliirtv inches in surface area. As shown in the fi ure representing the front of the arch tl i e door thereof is somewhat contracted.

The lines E E represent the door of the arch used for wood, and the lines F F show the height of the floor used for coal. The front opening of the arch constructed for coal i represented by the linesf 7, and is sixteen inches in widthabout eighteen inches in height. The upper part of this opening is half covered by a plate, which extends down to the lines g 9. Under the grate is the ordinary ash-pit, II, which is closed, and into it is led an air-pipe, 72, from any suitable air-forc ing engine. This is provided with a valve, 1', by means of which the blast may be regulated or altogether excluded. A branch of the main pipe is applied to the ashpit of each arch.

A pipe, K, is led across the face of the kiln just above the door with a branch pipe, 75, leading to the mouth of the kiln, preferably constructed so as to be swung up out of the -way whenevei it may be desired to do so, a coupling being provided at m to allow this. This pipe K is connected to any suitable source of supply of water or steam. I prefer to use water, as this is more convenient and serves the same purpose. I find it convenient to use the form shown inFigs. 5 and 6, in which it represents a cross-section of the pipenozzle with a hole at Zon the side toward the fire. This hole may be closed or regulated by means of the screw-plug L. A plate, M, is arranged, preferably, in horizontal position, so that the stream of water from the hole in the pipe strikes an inclination of the plate and is sprayed toward the coal and upon its surface, where it is immediately converted into steam and in part decomposed by the union of the oxygen with the incandescent coal.

The application of the water or steam in connection with the air-blast I find gives ample draft and volume of products of combustion of the proper temperature, so that the stone in the barrel of the kiln is heated uniformly throughout, so as to be uniformly and rapidly calcined without undue injury either to the arches or to the walls of the kiln. It

will be understood that the steam or the water pipes are provided with valves, by means of which this may be regulated or cut off.

It is well understood that when the fresh supply of coal is added to the fire or when the coal is stirred in the arch large volumes of carbon in finely-divided state or of carbon oxide are disengaged, which escape and pass through the stone in the barrel of the kiln unconsumed. In order to provide for the consumption of this carbon and carbonic oxide I provide an air-pipe, a, leading into each arch above the fuel with suitable valve for regulating the supply of air to the arch or eX cludin g it altogether, and when fresh coal is added or when the coal is stirred I turn on a blast of air in the pipe leading into this upper part of the arch. This supplies air to the arch above the fire-bed and facilitates the burning of the products of combustion,which would otherwise be unconsuined. The attendant at the kiln may readily determine by operating the valves and by observing the effect when he has a sufficient amount of air for the best effect both in the arch above the fire-bed and in the ash-pit below the grate; but it will be understood that the additional supply of air above the fire-bed is to be used only when additional coal is supplied.

I claim as my invention 1. The method of calcining rock in the manufacture of lime, consisting of, first, introducing an air-blast underneath the fuel in the kiln to increase the draft, and, second, introducing a spray of steam or water above the bed of coals, substantiall as and for the purpose described.

2. The hereinbefore-described mode of cal cining rock in a kiln having a barrel to contain the rock and arches leading thereto, consisting in applying an air-blast below the grate to create a draft, and in applying steam or a spray of water within the arch above the fuel to regulate the heat, as and for the purpose set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GRANVILLE E. OARIIETON.

\Vitnesses: N. T. TALBOT, O. F. RHTHAR'DS. 

